Since posting I picked up an E1e-BK off WTS (ty KennyC !!), which came with the stock MN01. I ordered and received an E-socket from Tad. I also picked up a LightSaver Miser tailcap (but the PWM is bad). Subsequently, though not looking for one, I found a deal on a custom bored E2E-HA w/ reversible clip, copper shroud & McClicky on eBay that was too good to pass up, but it didn't come with a lamp.
Love the E-socket and A3712 bipin lamps for 4.2V, which still give a nice lower output using 3V CR123A. Using AW IMR 16340 15C cells, I find that the light is too bright for nighttime use. I had intended to use the LightSaver moded tailcap, but found the PWM (which I can't see btw) to be intolerable. So I have been using 16340 only for daytime use, and swapping in CR123A for nighttime use, only using the Z61 tailcap.
When the bored E2E arrived, without a lamp, I decided to use my only Tad E-socket (intending to get more soon) with 18650 with it and use primaries in the E1e with the MN01, so I would have 2 compete and functional E-series lights until I get another E-socket.
But each morning, I found myself wanting to carry a brighter E1e, and so was swapping the E-socket back in the E1e with 16340.
Well, can you guess how I screwed up?
This morning when I swapped in the 16340, I forgot to swap in the E-socket which was still in the E2E. That poor MN01 breathed its last in a fraction of a second. :'(
When able, I'll be ordering TWO MORE E-sockets, even though I don't have a third E yet, to anticipate and also reduce the probability of screwing up again (because I will likely acquire more MN01 lamps that will come along with more E1e acquisitions).
So I have lost an MN01, and I'm back to one functional E-series light. What I have gained, however, is the wisdom that running CR123A primaries is perfectly valid, considering they are safer to run empty, they're triple the capacity of 16340, and Titanium Innovations CR123A (which selfbuilt himself uses) can be had from Battery Junction for just under a buck each in bulk with free ship. Even though the E1e is not regulated, I find that on CR123A the output is very constant for over an hour before it drops off.
I did not expect that running 16340's would be so bright! I think it is brighter than my incan A2 (also with Tad A2-socket w/ underdriven A4812 bipin lamp and 2x16340 8C). I also didn't expect the LightSaver incan PWM to bother me, but I can't tolerate it for more than a few minutes before I start to feel the brain-ache coming. Using a moded tailcap with 16340 was all part of the plan, for reduced brightness and increased runtime. But unless someone develops and offers a CC moded incan E-series tailcap, my E1e modes will be battery-driven only.